Procedures for forming an enclosure, for example forming a watertight shower enclosure, typically involve securing one or more substrate boards to a frame, e.g., wall studs, so that the substrate boards are in an upright position, subsequently affixing one or more ornamental features, such as tiles or stones, to the substrate boards, and then applying a sealer material between the ornamental features to seal the joint between adjacent ornamental features. Unfortunately, such procedures for forming the enclosure result in certain drawbacks for the installer. For example, the substrate boards are often heavy and very flexible prior to installation, which can make the installation process very difficult. Additionally, affixing the ornamental features after the substrate boards have been installed in an upright position can be problematic as the ornamental features may tend to move due to the forces of gravity, which can result in a sloppy looking finished product. Further, the wall studs to which the substrate boards are secured may include certain imperfections or abnormalities, e.g., knots, warping, wall studs that are out-of-plumb, etc. Consequently, the materials attached to the wall studs can likewise mimic the configuration of the wall studs, which may adversely impact the quality of the installation, and, thus, the quality and appearance of the finished product.